Edge controls for flooded nip coaters



Sept. 13, I966 w P. SORENSON ETAL 3,

EDGE CONTROLS FOR FLOODED NIP COATERS 2 Sheets-Sheet 1 Filed Aug. 15, 1963 INVENTOR. Sore/7601? Sept. 13, 1966 w. P. SORENSON ETAL 3,272,178

EDGE CONTROLS FOR FLOODED NIP COATERS Filed Aug. 15, 1963 2 Sheets-Sheet 2 INVENTOR.

BYFO er/ 5.496 1 a r/a dame: 6(81/ M $01 Wm TTORNEYS United States Patent 3,272,178 EDGE CONTROLS FOR FLOODED NIP COATERS Wayne 1P. Sorenson, Robert H. Shugarts, and James H. Riihl, Beloit, Wis, assignors to lBeloit Corporation, Beloit, Wis., a corporation of Wisconsin Filed Aug. 15, 1963, Ser. No. 302,309 3 Claims. (Cl. 118-249) This invention relates to improvements in devices for coating traveling webs of paper, and more particularly relates to marginal control means for a flooded nip coater for a traveling paper web.

The present invention has as a principal object to improve upon the marginal controls for coating traveling webs of paper.

Another object of the invention is to provide an improved coating device for coating traveling webs of paper by the use of an applicator roll, coat-ing the paper as it travels along a backing roll, in which improved means are provided for evening the coating of the paper along the edges of the web and preventing the flow of coating material onto opposite end portions of the backing roll.

Another object of the invention is to provide an improved coating device for coating traveling webs of paper and the like, operating on the flooded nip coating principle, and coating the paper as it travels along a backing roll, in which improved selectively operable means are provided for wiping coating material from the ends of the applicator roll in accordance with the width of the traveling web.

A further object of the invention is to improve upon the coaters heretofore in use having a backing roll and an applicator roll in nip defining relation with respect to the backing roll by providing selectively operable means to prevent the spreading of the coating material beyond the marginal edges of the web and onto the surface of the backing roll.

Still another object of the invention is to provide an improved device for coating a traveling sheet of paper which comprises a backing roll wrapped by the traveling web of paper, an applicator roll picking up coating material and applying it to the web on the backing roll, and a series of selectively operable wiper means extending inwardly from each end of the applicator roll and selectively operable to wipe the ends of the applicator roll free from coating material in accordance with the width of the web being wrapped.

These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings wherein:

FIGURE 1 is a view in side elevation of a flooded coater constructed in accordance with the principles of the present invention;

FIGURE 2 is a partial fragmentary view taken substantially along line IIII of FIGURE 1 with certain parts removed; and

FIGURE 3 is a diagrammatic view looking towards the nip of an applicator roll and backing roll and showing the end Wipes in transverse section.

In the embodiment of the invention illustrated in the drawings, generally designates a coating device, which comprises a backing roll or drum 11, which is wrapped by a traveling sheet or web W, and an applicator roll 12 picking up coating material M and applying it to the sheet W on the backing roll 11 in a coating nip N. The coating device also comprises circumferentially spaced wiper blades 15 and 16 extending axially inwardly from opposite ends of the applicator roll 12, for different distances, to wipe the ends of the applicator roll free from coating material M and selectively oper- 3,272,178 Patented Sept. 13, 1966 able for sheets of paper of diflerent widths to prevent the application of coating material to the marginal edges of the traveling sheet of paper W and to thereby prevent the flow of coating material onto the backing roll. The backing roll 11 is journalled at its ends in bearing supports 17 mounted on and extending from laterally spaced posts or columns 18 of a frame structure, which forms a supporting means for the coating structure. Spaced circumferentially from the outgoing side of the nip N between the rolls 11 and 12 is a doctor blade 19 mounted on a blade support 20 extending from a doctor back 21. The doctor back 21 is trunnioned at its opposite ends on trunnion pins 22 journalled in said bearing supports 23 mounted on a supporting frame structure 24 for the doctor back. The doctor back may be adjustably moved in a conventional manner to vary the pressure of the blade on the traveling web and to vary the angle of the blade with respect to the web. A drip plate 25 extends along the blade support 20 for substantially the length thereof, for returning coating material to a return trough 26 in a tank 27 for the coating material M.

The backing roll 11 is rotatably driven by a motor (not shown) in a suitable manner and receives the web 12 on its periphery for travel at the linear speed of the periphery of said roll. The drum 11 is of greater length (or transverse dimension with respect to the web W) than the web W, so as to assure the web W is backed by the drum 11 throughout its entire width. This leaves exposed edges of the drum surface on opposite sides of the web 11 and the instant invention provides means for avoiding the application of coating material M to these exposed drum edges and for leaving a slight marginal edge of the web W uncoated.

The applicator roll 12 is also driven from a suitable motor (not shown) and has a roll face 29 terminating inwardly of the exposed end portions of the surface of the backing roll 11, as shown in FIGURE 3. The applicator roll 12 is herein shown as being rotated in the direction of web travel and is usually driven at a slower rate of speed than the speed of travel of the web, although it may be driven at the same speed or at a higher speed for individual coating requirements. A nip N formed between the backing roll 11 and the applicator roll 12 may be such as to merely permit contact between the web W and the applicator roll 12 to the extent necessary to apply the coating material M at the nip N.

The extent of contact between the applicator roll 12 and the web W and their relative speeds may be correlated so that the web W removes coating material from the surface of the applicator roll 12 slightly more rapidly than the coating material is brought to the nip N, with the result that the coating material M is spread much more thinly on the web W than on the surface of the applicator roll 12. As will be seen, the applicator roll 12 is partially immersed in a bath of coating material M contained in a pan 30 mounted within the tank or trough 27. The amount of coating material M that is filmed onto the uprunning side of the applicator roll 12 may be controlled by variations in level of the coating material M in the pan 30, which level may be controlled so that the desired amount of coating material M is applied to the web W; and as has been pointed out, this amount is much less per unit of area on the web than the amount of coating material per unit of area on the applicator roll surface.

The doctor blade 19 thus serves to smooth the coating material rather than to actually wipe off any excess of coating material, but if any excess of coating material should occur, the drip plate 25 will return the coating material to the return trough 26.

The applicator roll 12 is mounted at its ends in bearing supports 33, 33 spaced outwardly beyond the ends of the pan 30. The bearing supports 33 at the ends of the applicator roll are supported on a vertical face 34 of an arm 35 of a lever arm 36. The lever arm 36 is pivoted intermediate its ends and adjacent its upper end portion on a transverse shaft 37 extending between the posts 18 and suitably mounted thereon. The lever arm 36 has a depending arm 39 extending downwardly toward the bottom of the post 18 and pivotally connected to a piston rod 40 extensible from a cylinder 41 suitably trunnioned to the post 18. The cylinder 41 has a piston (not shown) therein connected with the piston rod 40 and may be an air cylinder. Said cylinder and piston rod serve to retain the applicator roll 12 in position and to lower said applicator roll for cleaning or for training a new web about the backing roll 11. The applicator roll shaft (not shown) extends through end dams 42 closing the ends of the tank 27 and pan 30 in the operative position of the applicator roll. The ends of the tank 27 slide out of the end dams 42 upon lowering movement of the tank for cleaning and are of a well known construction so need not be shown or described further herein.

The tank 27 and pan 30 are mounted on arms 43 at opposite ends thereof, which arms are pivotally mounted on the shaft 37, to accommodate lowering of said tank and pan for cleaning. As shown in FIGURE 1, an individual cylinder 44 is suitably trunnioned to each post 18, intermediate its ends, and has a piston rod 45 exten sible therefrom. The piston rod 45 is pivotally connected between connector ears 46 extending rearwardly of the arm 43. The cylinders 44 may be air cylinders and serve to hold the tank 27 and pan 30 in the operative position shown in FIGURE 1 and to lower said tank and pan independently of lowering movement of the applicator roll 12, to accommodate cleaning of said tank and pan.

Referring now in particular to the end wipes 15 and 16, a pair of end wipes is provided on each end of applicator roll 12, for wiping the peripheral end surfaces of said roll. Said end wipes at each end of the applicator roll 12 are pivotally supported on the inside of an associated post 18 on a transverse pivot pin 47 and are of the same construction at each end of the roll so the end wipes on one end only of the appliactor roll, need be described in detail herein. The pivot pin 47 is mounted on a support bracket 48 extending along the top of a pad 49 and mounted thereon. The pad 49 is mounted on the top of a cross tie 50, suitably mounted between the posts 18, 13 and forming a pivotal support for the cross shaft 37.

The end wipe 16 is bolted or otherwise removably secured to the forward end of a wiper arm 51 and has a contoured or beveled advance wiping face engaging the periphery of the applicator roll 12. The wiper arm 51 has ears 53 depending therefrom intermediate the ends thereof and pivotally supported on the pivot pin 47. The arm 51 also has a depending rear end portion terminating in a horizontal ledge 55, to which is pivotally connected a piston rod 56 on a transverse pivot pin 57. The piston rod 56 is extensible from a cylinder 59 which may be an air cylinder and which is shown as being mounted on a transverse pivot pin 60 suitably mounted on an upstanding support 61 extending upwardly from a ledge 62, extending outwardly of the bracket 48. The cylinder 59 serves to withdraw the end wipe 16 from the periphery of the applicator roll 12 and to engage said end wipe with the periphery of said roll at a pressure, which may be selected by the pressure of air entering the cylinder 59.

The end wipe 15 is similar to the end wipe 16 and is bolted or otherwise secured to the end of an arm 63. The arm 63 has depending cars 62 pivoted to the transverse pivot pin 47. The arm 63 has a depending rear end portion 64 having a horizontal ledge 65 extending rearwardly therefrom, to which is pivotally connected a piston rod 66 extensible from a cylinder 67 suitably trunnioned to the ledge 62.

Suitable valves (not shown) may be provided to control the admission and release of air to the head and piston rod ends of the cylinders 59 and 67, to engage either end wipe 15 or 16 with the peripheral end portions of the appliactor roll 12, or to engage both end wipes with the peripheral portions of the said applicator roll for wide paper webs. The valves may load the end wipes at a required pressure and may enable a selected end wipe to be moved into wiping engagement with the applicator roll 12 under the control of the operator of the machine. The valves and the control therefor may be of a conventional form and are no part of the present invention, so need not herein be shown or described further.

In FIGURE 3, we have diagrammatically shown a part of a backing roll 11 and an applicator roll 12, and have illustrated the positions of the end wipes 15 and 16 with respect to the periphery of said applicator roll.

We have also shown a paper web A of one width trained about the backing roll 11 and passing into the nip N between said backing roll and applicator roll and have shown a sheet B wider than the sheet A. We have also shown the end wipe 15 wider than the end wipe 16. When a web of paper of width A is trained about the backing roll 11 through the nip N to be coated by the applicator roll 12, the cylinders 59 and 67 may be supplied with air under pressure to bring both end wipes into wiping engagement with the peripheral end portions of the applicator roll 12. Where the web is of width B, the cylinders 67 may be supplied with air under pressure to wipe the peripheral end portions of the applicator roll 12, and the end wipes 16 may be withdrawn from the peripheral end portions of the applicator roll.

It will be understood that various modifications and variations in the invention herein described may be effected without departing from the spirit and scope of the novel concepts of the present invention.

We claim as our invention:

1. In a device for coating a traveling paper web, in combination,

a backing roll wrapped by the traveling web and rotatably driven in one direction,

an applicator roll beneath said backing roll and with said backing roll defining a nip through which the paper web travels,

a pan containing coating material and having said applicator roll partially immersed in the coating material contained therein,

a doctor blade at the outgoing side of the nip between said rolls and engaging the coated paper web traveling about said applicator roll, for smoothing the coating material on the web,

and means on the incoming side of the nip between said rolls for controlling the application of coating to the edge portions of the web and preventing said doctor blade from spreading the coating material onto said backing roll comprising:

a pair of first and second end wipes extending inwardly from each of the opposite ends of the applicator roll on the incoming side of the nip between said rolls,

one of each pair of first and second end wipes extending axially inwardly along the applicator roll a greater distance than the other and engaging the peripheral surface of said applicator roll in overlapping and circumferentially spaced relation with respect to the other,

and individual actuators operatively connected with each of said end wipes and selectively operable to move a selected end wipe against the circumferential surface of said applicator roll in accordance with the width of the sheet being coated.

2. The structure of claim 1,

wherein the end wipes are mounted on and extend from the inner ends of individual wiper arms pivoted intermediate their ends for movement about a common axis parallel to the axis of rotation of the applicator roll,

wherein the actuators are pivoted to the opposite ends of the wiper arms from said end wipes and are independently operable to hold said end wipes in Wiping engagement of the surface of said applicator roll and to move either one of said end wipes out of wiping engagement with the surface of said applicator roll,

and wherein the wider end wipe extends over the narrower end wipe and engages the peripheral surface of the application roll in closer circumferentially spaced relation with respect to a nip between said applicator roll and said backing ro -ll than the narrower of said end Wipes.

3. The structure of claim 2, wherein the actuators are fluid pressure operated cylinders and pistons.

References Cited by the Examiner UNITED CHARLES A. WILLMUTH, Primary Examiner.

LEON G. MACHLIN, Assistant Examiner. 

1. IN A DEVICE FOR COATING A TRAVELING PAPER WEB, IN COMBINATION, A BACKING ROLL WRAPPED BY THE TRAVELING WEB AND ROTATABLY DRIVEN IN ONE DIRECTION, AN APPLICATOR ROLL BENEATH SAID BACKING ROLL AND WITH SAID BACKING ROLL DEFINING A NIP THROUGH WHICH THE PAPER WEB TRAVELS, A PAN CONTAINING COATING MATERIAL AND HAVING SAID APPLICATOR ROLL PARTIALLY IMMERSED IN THE COATING MATERIAL CONTAINED THEREIN, A DOCTOR BLADE AT THE OUTGOING SIDE OF THE NIP BETWEEN SAID ROLLS AND ENGAGING THE COATED PAPER WEB TRAVELING ABOUT SAID APPLICATOR ROLL, FOR SMOOTHING THE COATING MATERIAL ON THE WEB, AND MEANS ON THE INCOMING SIDE OF THE NIP BETWEEN SAID ROLLS FOR CONTROLLING THE APPLICATOR OF COATING TO THE EDGE PORTIONS OF THE WEB AND PREVENTING SAID DOCTOR BLADE FROM SPREADING THE COATING MATERIAL ONTO SAID BACKING ROLL COMPRISING: A PAIR OF FIRST AND SECOND END WIPES EXTENDING INWARDLY FROM EACH OF THE OPPOSITE ENDS OF THE APPLICATOR ROLL ON THE INCOMING SIDE OF THE NIP BETWEEN SAID ROLLS, ONE OF EACH PAIR OF FIRST AND SECOND END WIPES EXTENDING AXIALLY INWARDLY ALONG THE APPLICATOR ROLL A GREATER DISTANCE THAN THE OTHER AND ENGAGING THE PERIPHERAL SURFACE OF SAID APPLICATOR ROLL IN OVERLAPPING AND CIRCUMFERENTIALLY SPACED RELATION WITH RESPECT TO THE OTHER, AND INDIVIDUAL ACTUATORS OPERATIVELY CONNECTED WITH EACH OF SAID END WIPES AND SELECTIVELY OPERABLE TO MOVE A SELECTED END WIPE AGAINST THE CIRCUMFERENTIAL SURFACE OF SAID APPLICATOR ROLL IN ACCORDANCE WITH THE WIDTH OF THE SHEET BEING COATED. 